1. Field of the Invention
This disclosure relates to the field of digital data recovery in the event of a catastrophic event Specifically, it relates to the field of nearline data storage systems and methods that permit limited use of data and systems by virtual applications while the system is being repaired
2. Description of the Related Art
Individuals and corporations have long found it necessary to create backup copies of essential data and provide a means for returning the backup data to usable form. From carbon copies of handwritten documents stored in fireproof safes to digital replicas of massive quantities of data stored on offsite servers, the need for insurance that data will be available after a catastrophe has inspired numerous technological advances and an entire industry In this digital age, with its incredible amount of generated data and reliance on digital storage, secure data storage and disaster recovery will only become more crucial.
Data storage technologies are often measured by three criteria: accuracy, speed, and cost. Backup data should be as accurate as possible: that is, disparity between the backup data and the data at the time of the disaster must be minimal. Given that a data loss cripples a company, and that time is money, data recovery should also be efficient and expeditious Finally, solutions may present several different cost levels for businesses of different financial situations and priorities. Current solutions run from online “hot sites,” which continuously synchronize data and can restore that data almost immediately upon request, to offline “cold sites,” which are little more than a piecemeal space in which to coddle together data backups using shared equipment.
These present forms of digital data storage fall short of presenting an ideal balance of accuracy, speed, and cost, due to several problems. Firstly, replication hot sites, which provide the most accuracy and speed, are extraordinarily expensive. Hot sites constantly create backups, and store them in instantly usable formats that use a great deal of storage space. The effort and space involved in hot sites render them simply impractical for smaller businesses.
Second, more affordable restoration techniques used in cold sites are often too slow to restore business continuity after a disaster. Transforming compressed data stored on physical storage media, such as tapes or CDs, may require too much time. Even after transformation, the data must then be linked to the company's applications and users. This is usually accomplished by sending the data back to the business' main site. Cold sites require time to load data onto shared equipment, which may even need to be powered up or extricated from other jobs. These tasks are often only begun after a disaster occurs, further delaying a return to business continuity. During cold site data restoration, the data is not usable and business continuity is interrupted for an extended periods while the restoration is performed.
It is therefore desirable to achieve online hot sites' accuracy, instantaneous data availability, and minimal recovery time during a recovery, but with the lower cost of offline, cold sites. It is also desirable to have usable backup data available while in a recovery to allow ongoing business and meeting of critical deadlines. Such a compromise may be referred to herein as “near line.”
In addition, many backup and restoration systems rely on components that are just as prone to being destroyed in a catastrophe as the data they are meant to protect. For example, many storage media require physical restoration devices which, with an eye toward speedy recovery, may be kept on site. In addition, many disaster recovery systems rely on the same programs and servers used to access and process working data to access and process the backup data. With such a setup, the physical restoration devices and the native applications are just as vulnerable to a catastrophe and are not backed up, as they are the backup system. It is all too conceivable that a disaster would destroy both the primary data and the means for restoring backup data by destroying that server, leaving users with only a copy of the backup data and no means by which to restore or use it. Restoring native applications and finding replacement restoration devices in the event of such a catastrophe lengthens the period of business continuity interruption, increases cost, and takes manhours away from other recovery tasks. It is therefore desirable to have a data recovery system that does not rely on proprietary platforms stored onsite to restore data.
Finally, current storage solutions are excessively segmented in their offerings. Businesses must choose between preset “hot site” or “cold site” options that may not precisely fit their needs (i.e., what sorts of data or applications are available first; what human resources are necessary to restore business continuity, and the length of time necessary to restore business continuity) or budgets. It is therefore desirable to have a data recovery system that is customizable to fit business business needs and budgets, and which can be scaled in terms of immediacy of data accessibility and accuracy of backup data depending on an interplay of cost of backup operations compared to speed of recovery in the event of a disaster. This may be achieved by customizing how “live” data is and how often data is backed up